Hydrothermal liquefaction aqueous phase (HTL-AP) is complex and toxic, which severely hinders the scale-up of HTL technology. Distinguished from degrading organics and extracting chemical energy or nutrients from HTL-AP via biological fermentation or algae cultivation, here, we propose an innovative strategy to valorize the HTL-AP as a powerful anti-bacterial pool. Six model ingredients, i.e. lipids, cellulose, xylan, lignin, protein and the mixture were employed, to obtain a thirty-HTL-AP pool for characteristics database construction. We found that the xylan group at 230 °C on Escherichia coli (E. coli) and at 200 °C on Staphylococcus aureus (S. aureus) exhibited the highest anti-bacterial activities via plate experiments, nearly equal to 100 μg/ml streptomycin which far exceeded the working concentration of streptomycin (10–50 μg/ml). The liquid cultivation studies further revealed HTL-APs from the mixture feedstock, protein, real biomass microalgae and cornstalk had more stable anti-bacterial activities as chemically stable substances. Interestingly, the Gram-positive strain S. aureus was more susceptible than the Gram-negative E. coli on the HTL-APs, probably owing to the outer selectively permeable membrane difference and the strong reducibility and acidity of HTL-APs. This study provides a new vision to seek the anti-bacterial potential of HTL aqueous, supporting further investigations on its molecular mechanism and new bactericide development.

水热液化水相（HTL-AP）复杂且有毒，严重阻碍了HTL技术的规模化。与通过生物发酵或藻类培养降解有机物和从 HTL-AP 中提取化学能或营养物不同，我们在这里提出了一种创新策略，将 HTL-AP 用作强大的抗菌池。使用六种模型成分，即脂质、纤维素、木聚糖、木质素、蛋白质和混合物，获得用于特征数据库构建的三十个HTL-AP池。我们发现 230 °C 时在大肠杆菌( E. coli ) 和 200 °C 时在金黄色葡萄球菌( S. aureus ) 上的木聚糖基团) 通过平板实验显示出最高的抗菌活性，几乎等于 100 μg/ml 链霉素，远远超过链霉素的工作浓度（10-50 μg/ml）。液体培养研究进一步表明，混合原料、蛋白质、真正的生物质微藻和玉米杆中的HTL-AP作为化学稳定物质具有更稳定的抗菌活性。有趣的是，革兰氏阳性菌株金黄色葡萄球菌比革兰氏阴性大肠杆菌更敏感在 HTL-APs 上，可能是由于外部选择性渗透膜的差异和 HTL-APs 的强还原性和酸性。该研究为寻找HTL水的抗菌潜力提供了新的视野，支持对其分子机制的进一步研究和新型杀菌剂的开发。